So I went ahead and called the house wars in favor of the tiny little place that the guy seemed anxious to rent to me, I wrote saying I'd take it... and now I'm not hearing back from him

Meanwhile, my dad's scheme to get me a phone to use in the UK sounds like it's failed. He made me get an iPhone (I've never really wanted one of those things) because the clerk at the store said you can use them internationally, but, he didn't catch that that means with major roaming charges and huge fees on the data use, and that it means my number would still be US so only UK people who want to pay $1 a minute to talk to me could call me. So we have about 5 days to figure out another solution. Thing is I'm a cheapskate and I won't buy a phone for myself because I'm happy enough to use the internet for everything, and I really dislike setting up phones (wasted an hour or so on iPone stuff before we made our discovery, already); so if my dad's dream of getting me a phone is to be fulfilled we have to figure out something that he can pay for.

I agree with the above comments, it might be best to go for a pay as you go mobile when you get to the UK.
There should be lots of shops owned by different phone companies in Edinburgh, it's always best to shop around to get the best deal.